I am planning to buy a new computer and here are the parts that I have chosen:
CPU: Intel Core i7 7700K 4.2 Ghz
Mobo: GIGABYTE GA-Z270X Gaming 5
Memory: 16 GB (8GBx2) DDR4 3000Mhz
SSD: 250GB SAMSUNG 850 EVO
HDD: 2.0 TB 6Gbps TOSHIBA P300
Optical Drive: 24X LG SATA DUAL LAYER
Video Card: 6GB GTX 1060 GDDR5
Case: Corsair Black/Red Carbid Alpha
Power Supply: 750Watt eVGA SuperNova
I want to use it mainly for CAD softwares and ultimately gaming too :D; and I just want to know if this setting is going to be enough to last something like 2 to 3 years without replacing any part.
Thanks for the advice. But what about the gpu? I asked some computer scientist friends and they told me that I will probably have to change the gpu to gtx 1070 or 1080 after a year (year and half) for better rending. What do you think?
Depends what you want to do, a 6gb 1060 will handle 1080p just fine, if you want to push for 4k gaming then you will probably need a 1070. If you are willing to spend an infinite amount of money then I would say get a SLI pair of Titan X's if you really want top of the range but for what you want a 1060 will serve you just fine for a few years. The thing about computer components is that there isn't really such a thing as "Futureproof", the next big breakthrough in GPU technology could come next year and render all current cards obselete (very unlikely, but you get the idea). I would say that that is a very good system that will last you a good amount of time though.
If you do decide to get a 1070 you can save some money by getting an i5 processor. An i7 isn't necessary for CAD and gaming, usually they are only for video editing and other processor intensive processes. Most gaming setups with similar specs to yours will use an i5, as they are more than capable of handling anything you will be throwing at them by the sound of things.